Puzzling No-Start Issue

[98yellowsnk]

Bear with me, I have been searching the interwebs for over 2 weeks now, posted to Facebook groups and had very little luck. This forum will hopefully be my savior.
Need some help: 98 Cobra w/ PSC1 that has been on the car since almost new. Car has ran like a beast the four years I've owned it. Last Sunday, I got on it a little bit and noticed what seemed like bogging coming back down the RPM. Drove fine for the next 25+ miles. Went to get on the highway, revved up to about 4,500, felt the boost, then bog... I slowed down and felt what almost seemed like a serious loss of power. Stalled, would hard start, but start. It was only 12 miles to get home, so I nursed it along. I noticed I had very little power to start off, but once I got to my cruising speed (50-60mph) it was OK. Certainly not how it was. I barely made it home. Longshort , I've lost power to the fuel pump, injectors and spark/ coils. But it will hiccup with starter fluid. I tried my second set of keys for the PATS and no flashing Theft lamp. I am going with a module being failed, but not sure which direction as the internet has every sensor and computer to replace/ test, etc... I'm very mechanically inclined, but this is my first 4.6l and my first major issue with it. I'm a little puzzled at the moment because it happened so suddenly.

 

[ViciousBlack97]

The fact that you get anything with starting fluid at least signifies that the ignition system is still functioning. I'd start checking everything to do with the fuel system, starting with the inertia switch in the trunk. It would probably be wise to investigate the CCRM as well, as well as any related fuses.

 

[ViciousBlack97]

Also, this post may help with diagnosis of the CCRM if it is at fault.
http://forums.corral.net/forums/gt-...art-no-injector-pulse-no-power-fuel-pump.html

 

[aloo1]

My dad's 95 cobra would only start with starter spray and then the second you got on the throttle anymore than a couple hundred rpm's it would stall out... Replaced the MAF sensor and all was good. Look there to see if that could be an issue.

 

[98yellowsnk]

The fact that you get anything with starting fluid at least signifies that the ignition system is still functioning. I'd start checking everything to do with the fuel system, starting with the inertia switch in the trunk. It would probably be wise to investigate the CCRM as well, as well as any related fuses.

PATS fuse was blown. Now it hard starts and I have to maintenance throttle like an old 4 barrel without a choke. Going to get a scanner and see if anything pops up there. Since this happened I have replaced the external fuel pump and CCRM. Really don't want to start throwing parts at it. The fuel pump was original since the car was new (when SC was installed) and the CCRM was already an issue earlier in the year with my A/C clutch relay being blown. So I exchanged for another "new/ refab" one to be safe. Everything seems fine from that aspect.

 

[ViciousBlack97]

I'd check for any vacuum leaks as well. Just grab a can of carb cleaner and go to town around all of the gasket areas on the intake tract and manifold. The scan tool should be able to show the long and short term fuel trims. If they're crazy off, you can narrow the issue down.

 

[98yellowsnk]

oK - 99% sure I found the issue. The small harness to the left side coil bank had the middle wire rubbed through. It was a tight pinch in behind the SC bracket and something that must have been there a long time as I never touched that area - ever. I assume it either A) shorted the coil pack and/ or B) afterwards shorted out the PATS fuse and external fuel pump fuse. All I can figure. I ran a scan and came back with multiple PATS and coil bank failures. The spark plugs on the same failed coil were the only ones clean. Meaning they were not firing. I had to remove my strut brace or I probably could have diagnosed this faster, getting at all the plugs. Word to the wise. I think I'm good.